Stamping and loading apparatus



April 7, 1964 Filed June 8, 1961 L. C. BUFALINO STAMPING AND LOADING APPARATUS 2 Sheets-Sheet 1 INVENTOR. LOUIS C. BUFALINO ATTORNEYS April 7, 1964 c. BUFALINO 3,127,804

STAMPING AND LOADING APPARATUS Filed June 8, 1961 2 Sheets-Sheet 2 FIG. 2

INVE R. LOUIS C. BUFALI BY W,W+M

ATTORNEYS United States Patent Louis C. Bnfaiino, University Lane, Manchester, Mass.

Filed June 8, 1961, Ser. No. 115,821 8 Claims. (Cl. 83-96) This invention relates in general to the stamping of mica parts and in particular to the provision of stamped mica parts for automated mounting of electronic tubes.

In the construction of electronic tubes, it is necessary that the various electrodes be extremely accurately spaced from one another. Also, of course, it is necessary that the electrodes be properly supported. It has been the custom since very early in the history of tube manufacture to utilize mica as a spacing and supporting medium.

Mica is a rather unusual mineral which has certain qualities rendering it uniquely suitable for use in electronic tubes. First, it is an excellent insulator; second, it is capable of withstanding high temperatures; and lastly, it may be worked manually or by machine to very close tolerances. Usually, mica parts for tubes are in the form of thin flat slices, shaped as discs or other geometric forms suitable for engaging the inner wall of a glass bulb at several points.

The customary practice is to assemble, principally by hand, a mount in which the various electrodes of a tube are welded to leads passing through a glass stem. The ends of the electrodes adjacent to and opposite the stem are supported and held together in suitable spaced relationship by mica elements in which a predetermined pattern of holes has been punched to accommodate the various electrode ends. Prior to incorporating the mica parts into the tube mount, the mica is sprayed with alumina or other refractive material to prevent the formation of leakage paths over the surface of the mica.

In recent years, to cut down the amount of hand labor involved, automatic mounting machinery has been de veloped. In this machinery the mounts are assembled by machine, and all of the mount parts including the mica spacers must be available in quantity. This has given rise to problems to the various part manufacturers and particularly to manufacturers of mica spacers. Not only must the mica parts be delivered in quantity, but they must be oriented and stacked in such a manner that each may be delivered from a magazine in the proper condition and orientation for use by the automated machinery. Obviously, the mica spacers must also be precoated with the necessary refractory material, and finally, top and bottom surfaces, as determined by the direction of punching, must remain as such when the parts are stacked.

It is, therefore, a primary object of the present invention to supply mica parts for automated tube mounting.

It is another object of the present invention to stamp and magazine-load mica parts.

It is a further object of the present invention to decrease the cost and the handling of mica parts.

It is a still further object of the present invention to facilitate the automatic manufacture of electronic tubes.

In general, the present invention consists in the combination with a punch press of an automatic conveying and loading mechanism in which finished mica parts are stacked in a magazine for immediate assembly into electronic tubes. The punch press is modified by the inclusion of a mechanism for transferring stamped mica parts from a die to a conveyor mounted on the punch press. The conveyor is indexed from the stamping position to another position to which the parts are transferred from the conveyor into a magazine. Among the features of the invention are a recessed die which temporarily retains a mica part after it is stamped until a suitable receptacle on the conveyor is brought into register with 3,127,804 Fatented Apr. 7, 1964 the die. Transfer of the part from the die to the receptacle is effected by a knockout, and the part is then carried by the conveyor to a loading position. At the loading position, a detachable magazine is positioned above the conveyor. A loading ram is beneath the con veyor and an escapement mechanism is disposed adjacent the interior port of the magazine. The mica parts are accumulated by means of the escapement mechanism until the magazine is filled. For a better understanding of the present invention together with other and further objects, features and advantages, reference should be made to the following description which should be read in conjunction With the appended drawings, in which:

FIG. 1 is a front elevation, partly cut away and partly in section, of the punch press and conveyor of the invention;

FIG. 2 is a plan view of the embodiment of FIG. 1; and

FIG. 3 is a top view of a typical mica part as it is disposed in a receptacle of the conveyor.

In FIG. 1, there is shown a punch press 12 which includes a flywheel 13 which may include a one-revolution clutch or other suitable mechanism for periodically initiating a stamping cycle. Such punch presses are well known in the art, and certain modifications are made to permit their use for the stamping of mica parts. Considerable descriptive material on the presses and dies com monly used in stamping mica parts may be found in the American Machinst of September 13, 1954, in an article entitled Artists Sculpture Mica Dies.

A crank or suitable mechanism for punch press operation is supported on the shaft of the flywheel 13, details being omitted for purposes of simplification. An upper ram 15 driven by the crank 14 moves reciprocally to perform the stamping operation. It carries a ram adjusting screw 16, to which is attached a lower ram 17. The lower ram 17 is cut away in order that detail of the lower ram clamping arrangement may be seen. The ram reciprocates on the vertical standards 18, and it carries a knockout rod 20 which is adjustably positioned within a knockout block 21. A die base 23 is formed with a central opening through which the knockout rod passes. Knockout pins 25 extend from the lower end of the knockout rod to a knockout 27. A recess is formed in the lower surface of the die into which the knockout 27 fits.

Also mounted on the upper portion of the punch press is an air cylinder 29, the Working piston 31 of which is disposed closely adjacent the end of a lever 32. The lever 32 is pivoted at one end about an eye 33 and is spring-biased upward by means of a tension spring 34. The purpose and actual operation of this device are explained below.

An indexing conveyor or ring 35 substantially surrounds the frame of the punch press 12, and it includes. a plurality of uniformly spaced work areas. Each work area includes a relatively large opening 36 and a relatively small opening 37. In the position in which the indexing conveyor or ring 35 is shown, the large opening 36 is in register with the die 2d. Immediately beneath the large opening there may be seen a bottom punch 3% which passes through an opening formed in the stripper 40.

At the left of the punch and die as shown in the drawing is an air cylinder 41 supported on the press in position beneath the indexing ring 35. Above the ring 35 is a loading fixture 42, also supported by the frame of the press. It is a plate in which an opening is formed, and recessed in opposite sides of the opening are two springloaded pivoted escapement dogs 43 and 44. A fixed collar 45 is attached to the upper surface of the fixture 42, and a thumbscrew 46 is threaded through the collar 45. A magazine 47 is detachably held in position upon the loading fixture by means of the collar and clamping screw. A stacking plunger 48 is arranged to slide within the magazine 47 to bear upon accumulated mica parts.

The openings 37 in the ring 35 are successively positioned in register with the opening in the loading fixture 42 and with an opening formed in the support for the air cylinder 41. The cylinder41 has a movable shaft 49, shown in its retracted position, which when extended by actuation of the air cylinder passes through the aligned openings to force a mica past the escapement mechanism into the magazine 47. The stacking plunger holds accumulated mica parts by means of its weight and provides an indication of the number of parts in the magazine. A transverse slot 5% is formed at the mouth of the magazine 47 to permit the insertion of a flat stop rod and removal of the magazine without loss of parts when it is filled. In the plan view of FIG. 2, additional structural detail and the operation of the invention may be more easily seen. The basic punch press 12 includes a stationary table 51 at the back end of which an air cylinder 52 is mounted. A working shaft 53 extends from the air cylinder 52, and it is pivotally attached to the actuator arm 54. The actuator arm 54 is in turn pivoted about a central axis 55 which is also central to the indexing ring 35. Beneath the arm 54 is fixed an air cylinder 56, shown in outline, the movable shaft of which passes through an opening in the arm 54 and serves as a drive pin 58. A plurality of uniformly spaced holes 59 are formed about the inner periphery of the ring 35 to accommodate the drive pin 53 and to assure stopping of the ring at only desired positions. The latter function is performed by means of another air cylinder 61 and a stop pin 62 which is the movable shaft of the air cylinder. Suitable openings are provided in the plate 51 to permit the air cylinder movement and actuation.

The ring 35 rotates in a bed in the plate 51 and is maintained in position by four cleats 63. Other portions of the pieces are visible in this View, most of which have been described in connection with the discussion in FIG. 1. 'It may be seen that a mica part 71, such as shown in enlarged detail in FIG. 3, is in the die and that similar parts are carried in the various receptacles, one receptacle being in register with the magazine-loading mechanism. Additional detail, such as safety features, wiring and air lines have been eliminated or shown only for fragmentarily to avoid unnecessary complication of the drawing and to facilitate understanding of the invention.

The operation of the apparatus of the invention may be considerably modified by the introduction of automatic components, but is perhaps best understood by considering only a semi-automatic arrangement. The operator inserts a sheet of mica into the space above the punch 39 and depresses a foot switch. The foot switch causes the ram of the punch press to bring the die 26 through the opening 36 in the ring 35 down upon the mica. The mica part stamped from the sheet of mica is forced into the recess in the die 26 by the stamping action, the knockout 27 being retracted more deeply into the recess at that time. The subsequent action of the punch press is conventional in that after the punching stroke, the die is retraced to a position above the indexing ring 35.

At the same moment that the stamping action is taking place, the air cylinder 41 is also actuated by a solenoid valve or other suitable device controlled by the foot switch. The shaft 49 of the cylinder 41 is then extended through the aligned openings in its support, the loading fixture 42 and the mouth of the magazine 47 to a point beyond the escapement dogs 43 and 44. Continuing, however, with the action taking place in the stamping area, the air cylinder 56 is then actuated causing the drive pin 58 to move upwardly to one of the openings 59. Actuation of the air cylinder 56 may also be achieved by a solenoid valve or other suitable well known apparatus controlled in its time of operation by a timer or by micro-switches which are tripped by movement of the punching mechanism or by suitable cam members, After the drive pin 58 is in position, the air cylinder 52 is actuated in a manner similar to that described with reference to the air cylinder 56, causing its shaft 53 to move to the right as shown in FIG. 2. Movement of the shaft 53 causes the actuating arm 54 to pivot about the axis 55 from the position shown in unbroken lines to the position shown in broken lines. The ring 35 is turned through a few degrees as determined by the stroke of the arm 54. The air cylinder 61 is actuated, again in the same manner as previously described air cylinders, to raise its shaft carrying the stop pin 62 into another of the openings 59.

At this time one of the small openings 37, which serves as a receptacle for mica parts, is directly beneath the die 26. The air cylinder 29 is then actuated by a solenoid valve controlled by a timer or suitable switching devices, and its shaft 31 is extended to depress the lever 32. The lever 32 contacts the knockout arm 20 and the knockout 27 pushes a mica part into a receptacle 37.

The air cylinder 61 is again actuated to withdraw the stop pin 62, and the air cylinder 56 is actuated to Withdraw the drive pin 58. The arm 54 is withdrawn to the left by retraction of the shaft 53 of the air cylinder 52, after which the drive pin 58 is again raised, the shaft 53 is again extended and the ring 35 is once more indexed. Similarly, the air cylinder 61 is again actuated causing the stop pin 62 to enter the next opening 59 which is presented to it. Now, a large opening 36 is in register with the punch and die, and another small opening 37 is in register with the loading fixture 42. The ring remains in this position until the foot switch is again depressed to initiate another complete cycle.

No detailed showing of wiring diagrams, switches, timers, timing cams and cam shafts or of air lines, compressors or solenoid valves has been made because these are not believed to be of the essence of the invention, and suitable arrangements for timing and actuating such devices are widely known in the art and described in standard engineering texts. A cam shaft carrying a series of cams and driven by a constant speed motor could be utilized to trip switches in the desired sequence, an electronic timer to close circuits in the desired sequence, microswitches arrayed about moving parts of the apparatus or any one of numerous well known arrangements will sufiice for the purposes of the invention.

The indexing ring 35 is usually made up into two pieces to permit its assembly about the punch press. It could, of course, take shapes other than that of a ring or even be constructed in a straight line. However, the design shown and described is presently preferred for convenience and structural simplicity.

As each mica part reaches the loading fixture, it is forced up into the magazine 47 by the shaft 49 of the air cylinder 41. Referring to FIG. 1, a considerable quantity of mica parts is shown to be accumulated in the magazine 47. Each part is added to the bottom of the stack until the magazine is filled. A suitable indicator can be placed on the shaft of the'stacking member 48 to show the quantity of parts present in the magazine 47 at any time. In addition to the indicating function, the stacking plunger 48 lightly compresses the stack and avoids bouncing or other mechanical action of the parts which might interfere with the uniform stacking which is necessary for subsequent automated feeding by the user.

When the magazine has been filled to the desired degree, a flat member is passed through the slot 50 to hold the accumulated parts in place in the magazine. The thumb screw 46 is loosened in the collar 45, and the magazine may then be withdrawn to be replaced by an empty magazine.

The nature of the mica material, as may be inferred from the description in the introductory portion of the specification, is unusual. No two sheets of mica are exactly the same, and considerable human judgment must be employed to get the maximum number of parts from a given sheet of material. It has been suggested that uniformly sized parts which are slightly oversize as compared to the finished parts may be prepunched. Such uniform prepunched parts could then be used as the raw material rather than a mica sheet. In such cases, automatic feeding of the slightly oversize parts to the apparatus of the invention would be practical.

Although what has been described and shown constitutes a preferred embodiment of the invention, numerous alternatives will suggest themselves to those skilled in the art upon a reading of the foregoing specification. Such alternatives are believed to be within the spirit and scope of the invention which should be limited only as required by the breadth of the appended claims.

What is claimed is:

1. In combination with a punch press, an indexing ring mounted for periodic rotation on said punch press, a punch and die actuated by said punch press for stamping mica parts, said indexing ring having openings formed therein for receiving said mica parts, said die having a recess formed therein for retaining each said stamped mica part during retraction of said die, means for indexing said ring during retraction of said die to bring said openings successively into alignment with said die, means for transferring each said mica part from said recess in said die into the opening of said indexing ring aligned therewith, a magazine supported by said punch press adjacent said ring, and means for transferring each said mica part from said openings to said magazine.

2. In combination with a punch press, an indexing conveyor mounted for periodic movement upon said punch press, a plurality of receptacles on said conveyor, means for periodically moving said indexing conveyor upon said punch press, a punch and die actuated by said punch press for stamping mica parts during rest periods of said indexing conveyor, means for retaining said parts in said die during periods of motion of said indexing conveyor, means on said die for transferring said mica parts to said receptacles during rest periods of said indexing conveyor, a magazine mounted adjacent said conveyor on said punch press, and means for transferring said mica parts from said receptacles to said magazine.

3. Apparatus for stamping and magazine-loading mica parts comprising an indexing ring mounted for periodic rotation upon said punch press, a punch and die actuated by said punch press for stamping said mica parts, means for indexing said ring following actuation of said punch and die, a plurality of receptacles for said parts being formed in said ring, each of said parts being retained in said die during indexing of said ring, an ejecting member in said die for transferring said parts from said die to said receptacles as each said receptacle is indexed into register therewith, a magazine supported upon said punch press above said ring, a loading ram disposed upon said punch press beneath said ring in alignment with said magazine, and means for actuating said loading ram to transfer said parts from said receptacles to said magazine as each said receptacle is brought into alignment therewith by the indexing motion of said ring.

4. In combination with a punch press, an indexing ring mounted for periodic rotation thereon, said indexing ring having a plurality of uniformly spaced openings formed therein, a punch disposed upon said press below said ring, a die normally disposed upon said press above said ring, means for actuating said die to stamp out a mica part from mica inserted between said punch and die, said die having a recess formed in the lower end thereof, means for retracting said die with a mica part retained in recess during retraction thereof, means for indexing said ring to bring one of said plurality of openings into position beneath said die, a knockout in said die, means for actuating said knockout to transfer said mica part from said recess to said one of said openings, a magazine disposed above said ring at a point removed from said punch and die, a loading ram disposed beneath said ring in register with said magazine, and means for actuating said loading ram to lift mica parts from said openings as each said opening is brought into register therewith by the indexing motion of said ring.

5. In apparatus as defined in claim 4, the further combination therewith of an escapement mechanism mounted on said punch press between said ring and said magazine, said loading ram lifting mica parts above said mechanism whereby a quantity of said parts may be accumulated in said magazine.

6. In combination with a punch press, a ring mounted for rotation upon said press, a punch disposed upon said press beneath said ring, a die normally disposed above said ring, means actuated by said press to bring said die down upon mica disposed on said punch to stamp out mica parts, openings being formed in said ring to permit the passage of said die, means for retracting said die, said die having a recess formed in the lower end thereof, a knockout disposed in said recess, each said mica part being retained in said recess during retraction of said die, means for indexing said ring after retraction of said die, means for actuating said knockout to transfer each said mica part to said ring after said ring indexes, a magazine disposed upon said press adjacent said ring, but remote from said punch and die, and means for transferring each said mica part into said magazine as said ring indexes said parts into register therewith.

7. In apparatus for stamping and magazine-loading mica parts, the combination with a punch press of an indexing ring mounted on said press, a first plurality of large openings being formed in said ring, a second plurality of small openings being formed in said ring, each small opening lying between two large openings, a punch and die actuated by said press to stamp said mica parts, said die passing through a large opening in said ring during each stamping operation and having a recess formed in its lower end for temporarily retaining a mica part after stamping, means for retracting said die, means for indexing said ring to bring one of said small openings into register with said die during retraction thereof, a knockout movable in said recess in said die, means for actuating said knockout to transfer said mica part from said recess to one of said small openings in said ring during retraction of said die, an escapement mechanism mounted on said press above said ring at a point removed from said punch and die, a detachable tubular magazine held by said escapement mechanism above said ring, and a load ing ram for pushing mica parts out of said small openings through said escapement mechanism into said magazine as each said small opening comes into register therewith during indexing of said ring.

8. Apparatus for stamping and magazine-loading of mica parts comprising a punch press, a ring mounted for indexing rotation upon said press, a plurality of uniformly spaced work areas formed in said ring, each said work area including at least a large opening and a small opening formed through said ring, said small opening having an upward-facing shoulder formed therein for supporting a mica part, a punch and die supported by said press at a first given point, means for indexing said ring periodically to align each said large opening successively with said punch and die, means for actuating said die to stamp a mica part from a sheet of mica inserted adjacent said large opening, means for retracting said die, means for retaining said mica part in said die during an indexing motion of said ring, means for arresting said indexing motion of said ring to hold one of said small openings beneath said die, means for ejecting said mica part into said small opening, said mica part resting on said shoulder formed therein, a magazine supported by said punch press adjacent said ring and spaced from said punch and die, and means for ejecting said mica part from said small opening into said magazine as said ring is indexed to bring said small opening into register there with.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Holz Oct. 8, 1889 Robinson et a1. Mar. 20, 1894 5 Mahoney June 22, 1915 Rockwood Oct. 28, 1930 5% Roedels Mar. 2, 193/ Nyquist Aug. 28, 1951 Segsworth Mar. 2, 1954 Chevallier Feb. 7, 1961 FOREIGN PATENTS Germany Mar. 31, 1955 

8. APPARATUS FOR STAMPING AND MAGAZINE-LOADING OF MICA PARTS COMPRISING A PUNCH PRESS, A RING MOUNTED FOR INDEXING ROTATION UPON SAID PRESS, A PLURALITY OF UNIFORMLY SPACED WORK AREAS FORMED IN SAID RING, EACH SAID WORK AREA INCLUDING AT LEAST A LARGE OPENING AND A SMALL OPENING FORMED THROUGH SAID RING, SAID SMALL OPENING HAVING AN UPWARD-FACING SHOULDER FORMED THEREIN FOR SUPPORTING A MICA PART, A PUNCH AND DIE SUPPORTED BY SAID PRESS AT A FIRST GIVEN POINT, MEANS FOR INDEXING SAID RING PERIODICALLY TO ALIGN EACH SAID LARGE OPENING SUCCESSIVELY WITH SAID PUNCH AND DIE, MEANS FOR ACTUATING SAID DIE TO STAMP A MICA PART FROM A SHEET OF MICA INSERTED ADJACENT SAID LARGE OPENING, MEANS FOR RETRACTING SAID DIE, MEANS FOR RETAINING SAID MICA PART IN SAID DIE DURING AN INDEXING MOTION OF SAID RING, MEANS FOR ARRESTING SAID INDEXING MOTION OF SAID RING TO HOLD ONE OF SAID SMALL OPENINGS BENEATH SAID DIE, MEANS FOR EJECTING SAID 